U.S. patent application number 17/009272 was filed with the patent office on 2020-12-17 for electrode assembly and polymer secondary battery cell including the same.
This patent application is currently assigned to LG Chem, Ltd.. The applicant listed for this patent is LG Chem, Ltd.. Invention is credited to Chang Bum Ahn, Myung Hoon Ko, Seung Ho Na, Ji Won Park.
Application Number | 20200395591 17/009272 |
Document ID | / |
Family ID | 1000005063081 |
Filed Date | 2020-12-17 |
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United States Patent
Application |
20200395591 |
Kind Code |
A1 |
Park; Ji Won ; et
al. |
December 17, 2020 |
Electrode Assembly And Polymer Secondary Battery Cell Including The
Same
Abstract
An electrode assembly includes a cell stack part having (a) a
structure in which one kind of radical unit is repeatedly disposed
and has same number of electrodes and separators which are
alternately disposed and integrally combined, or (b) a structure in
which at least two kinds of radical units are disposed in a
predetermined order, and an auxiliary unit disposed on at least one
among an uppermost part or a lowermost part of the cell stack part.
The one kind of radical unit of (a) has a four-layered structure in
which a first electrode, a first separator, a second electrode and
a second separator are sequentially stacked or a repeating
structure in which the four-layered structure is repeatedly
stacked, and each of the at least two kinds of radical units are
stacked by ones in the predetermined order to form the four-layered
structure or the repeating structure.
Inventors: |
Park; Ji Won; (Daejeon,
KR) ; Ko; Myung Hoon; (Daejeon, KR) ; Na;
Seung Ho; (Daejeon, KR) ; Ahn; Chang Bum;
(Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Chem, Ltd. |
Seoul |
|
KR |
|
|
Assignee: |
LG Chem, Ltd.
Seoul
KR
|
Family ID: |
1000005063081 |
Appl. No.: |
17/009272 |
Filed: |
September 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16534771 |
Aug 7, 2019 |
10804520 |
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17009272 |
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14469851 |
Aug 27, 2014 |
10418609 |
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16534771 |
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PCT/KR2014/001264 |
Feb 17, 2014 |
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14469851 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 10/0565 20130101;
H01M 2/24 20130101; H01M 10/0585 20130101; H01M 10/0436 20130101;
H01M 2300/0082 20130101; H01M 2/1061 20130101 |
International
Class: |
H01M 2/24 20060101
H01M002/24; H01M 2/10 20060101 H01M002/10; H01M 10/04 20060101
H01M010/04; H01M 10/0565 20060101 H01M010/0565; H01M 10/0585
20060101 H01M010/0585 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2013 |
KR |
10-2013-0016510 |
Feb 17, 2014 |
KR |
10-2014-0017698 |
Claims
1. An electrode assembly, comprising: a cell stack part having (a)
a structure in which one kind of radical unit is repeatedly
disposed such that each radical unit is disposed in direct contact
with an adjacent radical unit, the one kind of radical unit having
same number of electrodes and separators which are alternately
disposed and integrally combined, or (b) a structure in which at
least two kinds of radical units are disposed in a predetermined
order such that each radical unit is disposed in direct contact
with an adjacent radical unit according to the predetermined order,
the at least two kinds of radical units each having same number of
electrodes and separators which are alternately disposed and
integrally combined, a first auxiliary unit disposed on at least
one among an uppermost part or a lowermost part of the cell stack
part; and wherein the one kind of radical unit of (a) has a
four-layered structure in which a first electrode, a first
separator, a second electrode and a second separator are
sequentially stacked together or a repeating structure in which the
four-layered structure is repeatedly stacked, wherein each of the
at least two kinds of radical units of (b) are stacked by ones in
the predetermined order to form the four-layered structure or the
repeating structure in which the four-layered structure is
repeatedly stacked, wherein adjacent radical units are not combined
with each other in the cell stack part, or are combined with each
other in the cell stack part with a combining strength weaker than
a combining strength between the electrode and the separator in the
radical unit.
2. A method of manufacturing an electrode assembly, the method
comprising: a first step of forming one kind of a radical unit
having an alternately stacked structure of a same number of
electrodes and separators, or at least two kinds of radical units
having an alternately stacked structure of a same number of
electrodes and separators; a second step of forming a cell stack
part by repeatedly stacking the one kind of the radical units such
that each radical unit is disposed in direct contact with an
adjacent radical unit, or by stacking the at least two kinds of the
radical units in a predetermined order such that each radical unit
is disposed in direct contact with an adjacent radical unit
according to the predetermined order; and a third step of stacking
a first auxiliary unit on at least one among an uppermost part or a
lowermost part of the cell stack part, wherein the one kind of
radical unit has a four-layered structure in which a first
electrode, a first separator, a second electrode and a second
separator are sequentially stacked together or a repeating
structure in which the four-layered structure is repeatedly
stacked, wherein each of the at least two kinds of radical units
are stacked by ones in the predetermined order to form the
four-layered structure or the repeating structure in which the
four-layered structure is repeatedly stacked, wherein adjacent
radical units are not combined with each other in the cell stack
part, or are combined with each other in the cell stack part with a
combining strength weaker than a combining strength between the
electrode and the separator in the radical unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application No.
16/534,771, filed on Aug. 7, 2019, which is a continuation
application of U.S. application No. 14/469,851 filed on Aug. 27,
2014, now U.S. Pat. No. 10/418,609 issued on Sep. 17, 2019, which
is a U.S. national stage of International Application No.
PCT/KR2014/001264 filed Feb. 17, 2014, which claims priority to
Korean Patent Application No. 10-2013-16510 filed on Feb. 15, 2013
and Korean Patent Application No. 10-2014-17698 filed on Feb. 17,
2014. The applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to an electrode assembly and a
polymer secondary battery cell including the same, and more
particularly, to an electrode assembly having a novel structure
that is distinguished from a stack-type or a stack/folding type
structure and a polymer secondary battery cell including the
same.
Description of the Related Art
[0003] Secondary batteries ma ybe classified into various types
according to the structure of an electrode assembly. Typically,
secondary batteries may be classified into a stack-type, a
wrapping-type (a jelly-roll type), or a stack/folding type
according to the structure of an electrode assembly. The stack-type
structure may be obtained by separately stacking electrode units (a
cathode, a separator, and an anode) constituting the electrode
assembly, and thus an accurate alignment of the electrode assembly
is very difficult. In addition, a large number of processes are
necessary for the manufacture of the electrode assembly. The
stack/folding type structure is generally manufactured by using two
lamination apparatuses and one folding apparatus, and thus the
manufacture of the electrode assembly is very complicated.
Particularly, in the stack/folding type structure, full cells or
bi-cells are stacked through folding, and thus the alignment of the
full cells or the bi-cells is difficult.
SUMMARY OF THE INVENTION
[0004] An aspect of the present disclosure provides an electrode
assembly that is enabled to perform an accurate alignment and
simple process through a novel structure that is distinguished from
a stack-type or a stack/folding type structure, and a polymer
secondary battery cell including the same.
[0005] According to an aspect of the present disclosure, there is
provided an electrode assembly including a cell stack part having
(a) a structure in which one kind of radical unit is repeatedly
disposed, the one kind of radical unit having a same number of
electrodes and separators which are alternately disposed and
integrally combined, or (b) a structure in which at least two kinds
of radical units are disposed in a predetermined order, and an
auxiliary unit disposed on at least one among an uppermost part or
a lowermost part of the cell stack part. The one kind of radical
unit of (a) has a four-layered structure in which a first
electrode, a first separator, a second electrode and a second
separator are sequentially stacked together or a repeating
structure in which the four-layered structure is repeatedly
stacked, and each of the at least two kinds of radical units (b)
are stacked by ones in the predetermined order to form the
four-layered structure or the repeating structure in which the
four-layered structure is repeatedly stacked.
[0006] According to another aspect of the present disclosure, there
is provided a method of manufacturing an electrode assembly
including a first step of forming one kind of a radical unit having
an alternately stacked structure of a same number of electrodes and
separators, or at least two kinds of radical units having an
alternately stacked structure of a same number of electrodes and
separators; a second step of forming a cell stack part by
repeatedly stacking the one kind of the radical units, or by
stacking the at least two kinds of the radical units in a
predetermined order; and a third step of stacking an auxiliary unit
on at least one among an uppermost part or a lowermost part of the
cell stack part. The one kind of radical unit has a four-layered
structure in which a first electrode, a first separator, a second
electrode and a second separator are sequentially stacked together
or a repeating structure in which the four-layered structure is
repeatedly stacked, and each of the at least two kinds of radical
units are stacked by ones in the predetermined order to form the
four-layered structure or the repeating structure in which the
four-layered structure is repeatedly stacked.
[0007] The present disclosure may provide an electrode assembly
that is enabled to perform an accurate alignment and simple process
through a novel structure that is distinguished from a stack-type
or a stack/folding type structure, and a polymer secondary battery
cell including the same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other aspects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0009] FIG. 1 is a side view illustrating a first structure of a
radical unit according to the present disclosure;
[0010] FIG. 2 is a side view illustrating a second structure of a
radical unit according to the present disclosure;
[0011] FIG. 3 is a side view illustrating a cell stack part formed
by stacking the radical units of FIG. 1;
[0012] FIG. 4 is a side view illustrating a third structure of a
radical unit according to the present disclosure;
[0013] FIG. 5 is a side view illustrating a fourth structure of a
radical unit according to the present disclosure;
[0014] FIG. 6 is a side view illustrating a cell stack part formed
by stacking the radical units of FIG. 4 and the radical units of
FIG. 5;
[0015] FIG. 7 is a process diagram illustrating a manufacturing
process of a radical unit according to the present disclosure;
[0016] FIG. 8 is a perspective view illustrating a cell stack part
formed by stacking radical units having different sizes;
[0017] FIG. 9 is a side view illustrating the cell stack part of
FIG. 8;
[0018] FIG. 10 is a perspective view illustrating a cell stack part
formed by stacking radical units having different geometric
shapes;
[0019] FIG. 11 is a side view illustrating a first structure of a
cell stack part including a radical unit and a first auxiliary unit
according to the present disclosure;
[0020] FIG. 12 is a side view illustrating a second structure of a
cell stack part including a radical unit and a first auxiliary unit
according to the present disclosure;
[0021] FIG. 13 is a side view illustrating a third structure of a
cell stack part including a radical unit and a second auxiliary
unit according to the present disclosure;
[0022] FIG. 14 is a side view illustrating a fourth structure of a
cell stack part including a radical unit and a second auxiliary
unit according to the present disclosure;
[0023] FIG. 15 is a side view illustrating a fifth structure of a
cell stack part including a radical unit and a first auxiliary unit
according to the present disclosure;
[0024] FIG. 16 is a side view illustrating a sixth structure of a
cell stack part including a radical unit and a first auxiliary unit
according to the present disclosure;
[0025] FIG. 17 is a side view illustrating a seventh structure of a
cell stack part including a radical unit and a second auxiliary
unit according to the present disclosure;
[0026] FIG. 18 is a side view illustrating an eighth structure of a
cell stack part including a radical unit and a second auxiliary
unit according to the present disclosure;
[0027] FIG. 19 is a side view illustrating a ninth structure of a
cell stack part including a radical unit and a first auxiliary unit
according to the present disclosure;
[0028] FIG. 20 is a side view illustrating a tenth structure of a
cell stack part including a radical unit, a first auxiliary unit,
and a second auxiliary unit according to the present
disclosure;
[0029] FIG. 21 is a side view illustrating an eleventh structure of
a cell stack part including a radical unit and a second auxiliary
unit according to the present disclosure; and
[0030] FIG. 22 is a side view illustrating a polymer secondary
battery cell including an electrode assembly according to the
present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Exemplary embodiments of the present disclosure will now be
described in detail with reference to the accompanying drawings.
However, the present disclosure is not restricted or limited to the
following exemplary embodiments.
[0032] An electrode assembly according to the present disclosure
basically includes a cell stack part. Hereinafter, the cell stack
part will be explained first.
Cell Stack Part
[0033] The cell stack part has a structure obtained by repeatedly
disposing one kind of radical units or a structure obtained by
disposing at least two kinds of radical units in a predetermined
order, for example, alternately. This will be described below in
more detail.
Structure of Radical Unit
[0034] In an electrode assembly according to the present
disclosure, a radical unit is formed by alternately disposing
electrodes and separators. Here, the same number of electrodes and
separators are disposed. For example, as illustrated in FIG. 1 a
radical unit 110a may be formed by stacking two electrodes 111 and
113 and two separators 112 and 114. Here, a cathode and an anode
may naturally face each other through the separator. When the
radical unit is formed as described above, an electrode 111 is
positioned at one end of the radical unit (see the electrode 111 in
FIGS. 1 and 2) and a separator 114 is positioned at the other end
of the radical unit (see the separator 114 in FIGS. 1 and 2).
[0035] The electrode assembly according to the present disclosure
is basically characterized in that the cell stack part or electrode
assembly is formed by only stacking the radical units. That is, the
present disclosure has a basic characteristic in that the cell
stack part is formed by repeatedly stacking one kind of radical
unit or by stacking at least two kinds of radical units in a
predetermined order. To realize the above-described characteristic,
the radical unit may have the following structure.
[0036] First, the radical unit may be formed by stacking a first
electrode, a first separator, a second electrode, and a second
separator in sequence. In more detail, a first electrode 111, a
first separator 112, a second electrode 113, and a second separator
114 may be stacked in sequence from an upper side to a lower side,
as illustrated in FIG. 1, or from the lower side to the upper side,
as illustrated in FIG. 2, to form radical units 110a and 110b. The
radical unit having the above-described structure may be referred
to as a first radical unit. Here, the first electrode 111 and the
second electrode 113 may be opposite types of electrodes. For
example, when the first electrode 111 is a cathode, the second
electrode 113 may be an anode.
[0037] As described above, when the radical unit is formed by
stacking the first electrode 111, the first separator 112, the
second electrode 113, and the second separator 114 in sequence, a
cell stack part 100a may be formed by only repeatedly stacking the
one kind of radical units 110a, as illustrated in FIG. 3. Here, the
radical unit may have an eight-layered structure or twelve-layered
structure in addition to a four-layered structure. That is, the
radical unit may have a repeating structure in which the
four-layered structure is repeatedly disposed. For example, the
radical unit may be formed by stacking the first electrode 111, the
first separator 112, the second electrode 113, the second separator
114, the first electrode 111, the first separator 112, the second
electrode 113, and the second separator 114 in sequence.
[0038] Alternatively, the radical unit may be formed by stacking
the first electrode 111, the first separator 112, the second
electrode 113, the second separator 114, the first electrode 111,
and the first separator 112 in sequence, or by stacking the second
electrode 113, the second separator 114, the first electrode 111,
the first separator 112, the second electrode 113, and the second
separator 114 in sequence. The radical unit having the former
structure may be referred to as a second radical unit and the
radical unit having the latter structure may be referred to as a
third radical unit.
[0039] In more detail, the second radical unit 100c may be formed
by stacking the first electrode 111, the first separator 112, the
second electrode 113, the second separator 114, the first electrode
111, and the first separator 112 in sequence from the upper side to
the lower side, as illustrated in FIG. 4. Also, the third radical
structure 110d may be formed by stacking the second electrode 113,
the second separator 114, the first electrode 111, the first
separator 112, the second electrode 113, and the second separator
114 in sequence from the upper side to the lower side, as
illustrated in FIG. 5. As noted above, the stacking may be
conducted in sequence from the lower side to the upper side.
[0040] When only one of the second radical units 110c and one of
the third radical units 110d are stacked, a repeating structure in
which the four-layered structure is repeatedly stacked may be
formed. Thus, when the second radical unit 110c and the third
radical unit 110d are alternately stacked one by one, the cell
stack part 100b may be formed by stacking only the second and third
radical units, as illustrated in FIG. 6. For reference, when three
kinds of radical units are prepared, the cell stack part may be
formed by stacking the radical units in a predetermined order, for
example, the first radical unit, the second radical unit, the third
radical unit, the first radical unit again, the second radical
unit, and the third radical unit.
[0041] As described above, the one kind of radical unit in the
present disclosure has a four-layered structure in which a first
electrode, a first separator, a second electrode and a second
separator are sequentially stacked, or has a repeating structure in
which the four-layered structure is repeatedly stacked. Also, at
least two kinds of radical units in the present disclosure are
stacked only by ones in a predetermined order to form the
four-layered structure or the repeating structure in which the
four-layered structure is repeatedly disposed. For example, the
first radical unit forms a four-layered structure by itself, and
the second radical unit and the third radical unit form a
twelve-layered structure by stacking one of each, that is, two
radical units in total.
[0042] Thus, the cell stack part or electrode assembly may be
formed only by stacking, that is, by repeatedly stacking one kind
of radical unit or by stacking at least two kinds of radical units
in a predetermined order.
[0043] The cell stack part of the present disclosure may be formed
by stacking the radical units one by one. That is, the cell stack
part may be manufactured by forming the radical units and then
stacking the radical units repeatedly or in a predetermined order.
As described above, the cell stack part of the present disclosure
may be formed by only stacking the radical units. Therefore, the
radical units of the present disclosure may be very accurately
aligned. When the radical unit is accurately aligned, the electrode
and the separator may also be accurately aligned in the cell stack
part. In addition, the cell stack part or electrode assembly may be
improved in productivity. This is done because the manufacturing
process is very simple.
Manufacture of Radical Unit
[0044] A manufacturing process of the first radical unit will be
exemplarily described with reference to FIG. 7. First, a first
electrode material 121, a first separator material 122, a second
electrode material 123 and a second separator material 124 are
prepared. Here, the first separator material 122 and the second
separator material 124 may be the same. The first electrode
material 121 is cut into a certain size through a cutter C1, and
the second electrode material 123 is cut into a certain size
through a cutter C2. Then, the first electrode material 121 is
stacked on the first separator material 122, and the second
electrode material 123 is stacked on the second separator material
124.
[0045] Then, it is preferable that the electrode materials and the
separator materials are attached to each other through laminators
L1 and L2. Through the attachment, a radical unit in which the
electrodes and the separators are integrally combined may be
formed. The combining method may be diverse. The laminators L1 and
L2 may apply pressure to the materials or apply pressure and heat
to the materials to attach the materials to each other. Because of
the attachment, the stacking of the radical units may be more
easily performed while manufacturing the cell stack part. Also, the
alignment of the radical units may be also easily accomplished
because of the attachment. After the attachment, the first
separator material 122 and the second separator material 124 are
cut into a certain size through a cutter C3 to manufacture the
radical unit 110a. During this process, the edges of the separators
are not joined with each other.
[0046] As described above, the electrode may be attached to the
adjacent separator in the radical unit. Alternatively, the
separator may be attached to the adjacent electrode. Here, it is
preferable that an entire surface of the electrode facing the
adjacent separator is attached to the adjacent separator. In this
case, the electrode may be stably fixed to the separator.
Typically, the electrode has a size less than that of the
separator.
[0047] For this, an adhesive may be applied to the separator.
However, when the adhesive is used, it is necessary to apply the
adhesive over an adhesion surface of the separator in a mesh or dot
shape. This is because if the adhesive is closely applied to the
entire adhesion surface, reactive ions such as lithium ions may not
pass through the separator. Thus, when the adhesive is used, it is
difficult to allow the overall surface of the electrode to closely
attach to the adjacent separator.
[0048] Alternatively, use of the separator including the coating
layer having adhesive strength makes it possible to generally
attach the electrode to the separator. This will be described below
in more detail. The separator may include a porous separator base
material such as a polyolefin-based separator base material and a
porous coating layer that is generally applied to one side or both
sides of the separator base material. Here, the coating layer may
be formed of a mixture of inorganic particles and a binder polymer
that binds and fixes the inorganic particles to each other.
[0049] Here, the inorganic particles may improve thermal stability
of the separator. That is, the inorganic particles may prevent the
separator from being contracted at a high temperature. In addition,
the binder polymer may fix the inorganic particles to improve
mechanical stability of the separator. Also, the binder polymer may
attach the electrode to the separator. Since the binder polymer is
generally distributed in the coating layer, the electrode may
closely adhere to the entire adhesion surface of the separator,
unlike the foregoing adhesive. Thus, when the separator is used as
described above, the electrode may be more stably fixed to the
separator. To enhance the adhesion, the above-described laminators
may be used.
[0050] The inorganic particles may have a densely packed structure
to form interstitial volumes between the inorganic particles over
the overall coating layer. Here, a pore structure may be formed in
the coating layer by the interstitial volumes that are defined by
the inorganic particles. Due to the pore structure, even though the
coating layer is formed on the separator, the lithium ions may
smoothly pass through the separator. For reference, the
interstitial volume defined by the inorganic particles may be
blocked by the binder polymer according to a position thereof.
[0051] Here, the densely packed structure may be explained as a
structure in which gravels are contained in a glass bottle. Thus,
when the inorganic particles form the densely packed structure, the
interstitial volumes between the inorganic particles are not
locally formed in the coating layer, but generally formed in the
coating layer. As a result, when each of the inorganic particles
increases in size, the pore formed by the interstitial volume also
increases in size. Due the above-described densely packed
structure, the lithium ions may smoothly pass through the separator
over the entire surface of the separator.
[0052] The radical units may also adhere to each other in the cell
stack part. For example, if the adhesive or the above-described
coating layer is applied to a bottom surface of the second
separator 114 in FIG. 1, the other radical unit may adhere to the
bottom surface of the second separator 114.
[0053] Here, the adhesive strength between the electrode and the
separator in the radical unit may be greater than that between the
radical units in the cell stack part. It is understood, that the
adhesive strength between the radical units may not be provided. In
this case, when the electrode assembly or the cell stack part is
disassembled, the electrode assembly may be separated into the
radical units due to a difference in the adhesive strength. For
reference, the adhesive strength may be expressed as delamination
strength. For example, the adhesive strength between the electrode
and the separator may be expressed as a force required for
separating the electrode from the separator. In this manner, the
radical unit may not be bonded to the adjacent radical unit in the
cell stack part, or may be bonded to the adjacent radical unit in
the cell stack part by means of a bonding strength differing from a
bonding strength between the electrode and the separator.
[0054] For reference, when the separator includes the
above-described coating layer, it is not preferable to perform
ultrasonic welding on the separator. Typically, the separator has a
size greater than that of the electrode. Thus, there may be an
attempt to bond the edge of the first separator 112 to the edge of
the second separator 114 through the ultrasonic welding. Here, it
is necessary to directly press an object to be welded through a
horn in the ultrasonic welding. However, when the edge of the
separator is directly pressed through the horn, the separator may
adhere to the horn due to the coating layer having the adhesive
strength. As a result, the welding apparatus may be broken
down.
Modification of Radical Unit
[0055] Until now, the radical units having the same size have been
explained. However, the radical units may have different sizes.
When stacking the radical units having different sizes, cell stack
parts having various shapes may be manufactured. Herein, the size
of the radical unit is explained with reference to the size of the
separator, because, typically, the separator is larger than the
electrode.
[0056] Referring to FIGS. 8 and 9, a plurality of radical units is
prepared and may be classified into at least two groups having
different sizes (see reference numerals 1101a, 1102a and 1103a in
FIG. 9). By stacking the radical units according to their sizes, a
cell stack part 100c having a structure of a plurality of steps may
be formed. FIGS. 8 and 9 illustrate an embodiment in which the cell
stack part includes three steps obtained by stacking the radical
units 1101a, 1102a and 1103a classified into three groups, in which
the radical units having the same size are stacked together, is
illustrated. Thus, the cell stack part 100c in FIGS. 8 and 9 have a
structure including three steps. For reference, the radical units
included in one group may form two or more steps.
[0057] When the plurality of steps is formed as described above, it
is preferable that the radical unit has a structure of the first
radical unit, that is, the above-described four-layered structure
or the repeating structure in which the four-layered structure is
repeatedly stacked. (Herein, the radical units are considered to be
included in one kind of radical unit even though the radical units
have the same stacked structures of the but have different
sizes.)
[0058] Preferably, the same number of cathodes and the anodes are
stacked in one step. Also, it is preferable that opposite
electrodes face each other through a separator between one step and
another step. For example, in case of the second and third radical
units, two kinds of the radical units are necessary for forming one
step.
[0059] However, incase of the first radical unit, only one kind of
radical unit is necessary for forming one step as illustrated in
FIG. 9. Thus, when the radical unit has the four-layered structure
or the repeating structure in which the four-layered structure is
repeatedly stacked, number of kinds of radical units may decrease
even though a plurality of the steps is formed.
[0060] Also, in case of the second and the third radical units, at
least one of the two kinds of the radical units are necessary to be
stacked to form one step. Thus, the one step may have at least a
twelve-layered structure. However, in case of the first radical
unit, only one kind of radical unit is necessary to be stacked to
form one step. Thus, one step may have at least a four-layered
structure. As a result, when the radical unit has the four-layered
structure or the repeating structure in which the four-layered
structure is repeatedly stacked, the thickness of each step may be
easily controlled when forming a plurality of steps.
[0061] The radical units may have not only different sizes but also
different geometric shapes. For example, the radical units may have
different sizes and different edge shapes, and may or may not have
a through hole as illustrated in FIG. 10. More particularly, as
illustrated in FIG. 10, a plurality of radical units classified
into three groups may form three steps by stacking the radical
units having the same geometric shapes.
[0062] For this, the radical units may be classified into at least
two groups (each of the groups has different geometric shape).
Similarly, the radical unit may preferably have the four-layered
structure or the repeating structure in which the four-layered
structures are repeatedly stacked, that is, the structure of the
first radical unit. (Herein, the radical units are considered to be
included in one kind of radical unit even though the radical units
have the same stacked structure but have different geometric
shapes.)
Auxiliary Unit
[0063] The electrode assembly according to the present disclosure
may further include an auxiliary unit stacked on at least one among
the uppermost part or the lowermost part of the cell stack
part.
[0064] The auxiliary unit may include a first auxiliary unit and a
second auxiliary unit. First, the first auxiliary unit will be
described below. In the present disclosure, an electrode is
positioned at one end of the radical unit, and a separator is
positioned at the other end of the radical unit. When the radical
units are stacked in sequence, the electrode may be positioned at
the uppermost portion or at the lowermost portion of the cell stack
part (see reference numeral 116 in FIG. 11, and this electrode may
be referred to as a terminal electrode 116). The first auxiliary
unit is additionally stacked on the terminal electrode.
[0065] In more detail, when the terminal electrode 116 is a
cathode, the first auxiliary unit 130a may be formed by stacking
outward from the terminal electrode 116, a separator 114, an anode
113, a separator 112, and a cathode 111 in sequence, as illustrated
in FIG. 11. On the other hand, when the terminal electrode 116 is
an anode, the first auxiliary unit 130b may be formed by stacking
outward from the terminal electrode 116, the separator 114, and the
cathode 113 in sequence, as illustrated in FIG. 12. In this case, a
separator may be further stacked on the outer side of the first
auxiliary unit as occasion demands.
[0066] In the electrode assembly according to the present
disclosure, a cathode may be positioned at the outermost portion of
a terminal electrode through the first auxiliary units 130a and
130b stacked in the cell stack parts 100d and 100e, as illustrated
in FIGS. 11 and 12. In this case, in the cathode positioned at the
outermost portion, that is, the cathode of the first auxiliary
unit, an active material layer is preferably coated on only one
side facing the radical unit (one side facing downward in FIG. 11)
among both sides of the current collector. When the one side of the
current collector is coated with the active material layer as
described above, the active material layer is not positioned at the
outermost portion of the cell stack part. Thus, waste of the active
material layer may be prevented. For reference, since the cathode
emits, for example, lithium ions, when the cathode is positioned at
the outermost portion, the capacity of a battery may be
improved.
[0067] Next, a second auxiliary unit will be described below. The
second auxiliary unit performs the same function as the first
auxiliary unit, which will be described below in more detail. In
the present disclosure, an electrode is positioned at one end of
the radical unit, and a separator is positioned at the other end of
the radical unit. When the radical units are stacked in sequence,
the separator may be positioned at the uppermost portion or at the
lowermost portion of the cell stack part (see reference numeral 117
in FIG. 13, and this separator may be referred to as a terminal
separator 117). The second auxiliary unit is additionally stacked
on the terminal separator.
[0068] In more detail, when the electrode 113 contacting the
terminal separator 117 is a cathode in the radical unit, the second
auxiliary unit 140a may be formed by stacking from the terminal
separator 117, an anode 111, a separator 112, and a cathode 113 in
sequence, as illustrated in FIG. 13. On the other hand, when the
electrode 113 contacting the terminal separator 117 is an anode in
the radical unit, the second auxiliary unit 140b may be formed as
the cathode 111, as illustrated in FIG. 14.
[0069] In the electrode assembly according to the present
disclosure, a cathode may be positioned at the outermost portion of
a terminal separator through the second auxiliary units 140a and
140b stacked in the cell stack parts 100f and 100g, as illustrated
in FIGS. 13 and 14. In this case, in the cathode positioned at the
outermost portion, that is, the cathode of the second auxiliary
unit, an active material layer is preferably coated on only one
side facing the radical unit (one side facing upward in FIG. 13)
among both sides of the current collector, as similar to the
cathode of the first auxiliary unit.
[0070] The first auxiliary unit and the second auxiliary unit may
have different structures from those described above. First, the
first auxiliary unit will be described below. When the terminal
electrode 116 is a cathode as illustrated in FIG. 15, the first
auxiliary unit 130c may be formed by stacking from the terminal
electrode 116, a separator 114, and an anode 113 in sequence. On
the other hand, when the terminal electrode 116 is an anode as
illustrated in FIG. 16, the first auxiliary unit 130d may be formed
by stacking from the terminal electrode 116, a separator 114, a
cathode 113, a separator 112, and an anode 111 in sequence.
[0071] In the electrode assembly according to the present
disclosure, an anode may be positioned at the outermost portion of
the terminal electrode through the first auxiliary units 130c and
130d stacked in the cell stack parts 100h and 100i as illustrated
in FIGS. 15 and 16.
[0072] Next, the second auxiliary unit will be described below. As
illustrated in FIG. 17, when the electrode 113 contacting the
terminal separator 117 is a cathode in the radical unit, the second
auxiliary unit 140c may be formed as an anode 111. As illustrated
in FIG. 18, when the electrode 113 contacting the terminal
separator 117 is an anode in the radical unit, the second auxiliary
unit 140d may be formed by stacking from the terminal separator
117, the cathode 111, the separator 112, and the anode 113 in
sequence.
[0073] In the electrode assembly according to the present
disclosure, an anode may be positioned at the outermost portion of
the terminal separator through the second auxiliary units 140c and
140d stacked in the cell stack parts 100j and 100k, as illustrated
in FIGS. 17 and 18.
[0074] For reference, an anode may make a reaction with an aluminum
layer of a battery case (for example, a pouch-type case) due to
potential difference. Thus, the anode is preferably insulated from
the battery case by means of a separator. For this, the first and
second auxiliary units in FIGS. 15 to 18 may further include a
separator at the outer portion of the anode. For example, the first
auxiliary unit 130e in FIG. 19 may further include a separator 112
at the outermost portion thereof when compared with the first
auxiliary unit 130c in FIG. 15. For reference, when the auxiliary
unit includes the separator, the alignment of the auxiliary units
in the radical unit may be easily performed.
[0075] A cell stack part 100m and an electrode assembly in which
first and second auxiliary units 130f and 140e are stacked on the
cell stack part 100m may be formed as illustrated in FIG. 20. A
radical unit 110b may be formed by stacking from the lower portion
to the upper portion, a first electrode 111, a first separator 112,
a second electrode 113, and a second separator 114 in sequence. In
this case, the first electrode 111 may be a cathode, and the second
electrode 113 may be an anode.
[0076] A first auxiliary unit 130f may be formed by stacking from
the terminal electrode 116, the separator 114, the anode 113, the
separator 112 and the cathode 111 in sequence. In this case, in the
cathode 111 of the first auxiliary unit 130f, only one side of a
current collector facing the radical unit 110b among both sides of
the current collector may be coated with an active material
layer.
[0077] Also, a second auxiliary unit 140e may be formed by stacking
from the terminal separator 117, the cathode 111 (the first
cathode), the separator 112, the anode 113, the separator 114, and
the cathode 118 (the second cathode) in sequence. In this case, in
the cathode 118 (the second cathode) of the second auxiliary unit
140e positioned at the outermost portion, only one side of a
current collector facing the radical unit 110b among both sides of
the current collector may be coated with an active material
layer.
[0078] Finally, a cell stack part 100n and an electrode assembly in
which a second auxiliary unit 140f is stacked on the lowermost part
of the cell stack part 100n may be formed as illustrated in FIG.
21.
[0079] In this case, a radical unit 110e may be formed by stacking
from the upper portion to the lower portion, a first electrode 111,
a first separator 112, a second electrode 113, and a second
separator 114 in sequence. In this case, the first electrode 111
may be an anode, and the second electrode 113 may be a cathode.
Also, a second auxiliary unit 140f may be formed by stacking from
the terminal separator 117, the anode 111, the separator 112, the
cathode 113, the separator 114, and the anode 119 in sequence.
Polymer Secondary Battery Cell Including Electrode Assembly
[0080] In the present disclosure, a polymer secondary battery cell
including the above-described electrode assembly may be
manufactured.
[0081] For example, the polymer secondary battery cell according to
the present disclosure may include an electrode assembly including
a cell stack part 100 and an auxiliary unit, a fixing part 200 for
fixing the cell stack part 100 and the auxiliary unit, and a pouch
case 300 for accommodating the fixing part 200 and the electrode
assembly, as illustrated in FIGS. 22.
[0082] The auxiliary unit may include first and second auxiliary
units 130 and 140. As the fixing part 200, a polymer tape
exhibiting adhesiveness when soaked in water may be used.
[0083] That is, the electrode assembly including the cell stack
part 100 may include first and second auxiliary units 130 and 140
stacked on the uppermost part or the lowermost part of the cell
stack part 100, respectively and the fixing part 200 may fix the
cell stack part 100b and the first and second auxiliary units 130
and 140.
[0084] Therefore, the polymer secondary battery cell according to
the present disclosure includes an electrode assembly having a
novel structure that is distinguished from a stack-type or a
stack/folding type structure. The stacking method of the electrode
assembly may be simplified, and commercial value of a product may
be improved.
[0085] While the present invention has been shown and described in
connection with the exemplary embodiments, it will be apparent to
those skilled in the art that modifications and variations can be
made without departing from the spirit and scope of the invention
as defined by the appended claims.
* * * * *